Apparatus and methods for the purifying of biomolecules via an adsorption to magnetizable particles are known in the art. The known methods are determined by the type of biomolecules and an interaction of the biomolecules with the magnetizable particles. These known methods of purifying are adapted for an automation of the methods for the purifying of biomolecules.
Among known suppliers of apparatus and methods for the purifying of biomolecules are: Chemagen, Qiagen, Thermo, Promega, Roche Diagnostics, Agowa, Dynal, Thermo Fisher, Analytik Jena and Tecan.
The known suppliers have partly protected their apparatus through their own patents (for example WO 03/044537, WO 2007/020294, U.S. Pat. No. 6,448,092 and WO 9609550).
Most of the known apparatus have in common that they are so-called magnet separators without a pipetting function (Thermo Kingfisher, Promega, Agowa). An operator pipettes solutions prior to an extraction process of the biomolecules by hand, or the operator uses prefilled plastic cavities for the extraction process of the biomolecules. In an apparatus supplied by Chemagen the cavities are also pre-filled, but an eluate still needs to be removed by pipetting manually. These approaches are sufficient for applications in research; however, they are not sufficient for diagnostics.
An apparatus offering a further solution is the Magnapure technology by Roche Diagnostics.
European patent application No. 0 644 425 by Hoffmann-La Roche discloses an analysis apparatus with a device for separating magnetic microparticles from a suspension. The apparatus disclosed in the Hoffmann-La Roche application comprises two permanent magnets between which a reaction cavity containing the suspension is disposed. The permanent magnets are arranged diametrically opposite each other with respect to the reaction cavity. The polar axes of the permanent magnets and the longitudinal axis of the reaction cavity form an acute angle. With this arrangement of the polar axes the magnetic stray field can be used for the separation of the magnetic microparticles, thereby accelerating the separation of the magnetic microparticles.
U.S. Pat. No. 6,596,162 (Thermo Labsystems Oy) and U.S. Pat. No. 6,040,192 (Labsystems Oy) disclose an apparatus for separating magnetic particles from a reaction cavity with a removable permanent magnet.
A use of the permanent magnets and suspensions with magnetic particles is common to the known apparatus. The magnetic particles are collected from the suspension and adhere to the permanent magnet due to the magnetic force. The magnetizable particles are released again after removing the magnetic field.
U.S. Pat. No. 6,409,925 B1 (Bio-Magnetics Ltd.) discloses an apparatus for a collecting of magnetic particles as well as a transferring of the magnetic particles from a first cavity to a second cavity. For the collecting and the transferring of the magnetic particles teaches a mobile magnetic element in order to magnetize a tip. A magnetization of the tip occurs upon approaching the mobile magnetic element to the tip. The magnetized tip is adapted for the collecting and the transferring of the magnetic particles.
EP 1 726 963 A2 (Festo Corporation) discloses a system for transferring a sample material from a source cavity to a target cavity. A transfer unit comprises at least one pin tip with a central bore and a magnetic actuator element. The actuator element is moveable between a first and a second actuator position. The sample material in proximity of the pin tip is either collected or released by moving the actuator element. Furthermore a group of counter magnets is provided underneath the source cavity and/or the target cavity, in order to support the transferring of the sample material. The Festo application furthermore allows a common movement of the actuator element and the group of counter magnets in order to mix the sample material. Each of the pin tips is individually controllable; likewise, a movement of each of the counter magnets is individually controllable.
The above-mentioned solutions have a disadvantage of qualitative shortcomings in a production of an eluate. The majority of the above mentioned solutions do not fulfill requirements of in-vitro diagnostics.
The purifying of the biomolecules using the magnetizable particles leads to “residual particles” in the eluate according to the methods known in the art. The “residual particles” have to be removed at a great effort in a further process step, for example, by centrifugation, since the “residual particles” impair subsequent analytic processes.
So far the purifying of the biomolecules comprised numerous sources of errors. The numerous sources of errors typically lead to at least one of a contamination, falsely negative results or falsely positive results. The numerous sources of errors are due to the chain of process steps. The process steps comprise a lysis of the sample material, a selection of substances and reagents. The process steps yield the eluate.
Furthermore, there is a danger of confusion when combining substances within a kit used for the purifying of biomolecules. A kit consists of a defined combination of substances and reagents. The substances and the reagents comprise, for example, an elution buffer. A use of a wrong elution buffer would, for example, lead to the biomolecules no longer being separable from the biomolecules bound to the magnetizable particles using the elution buffer. Thus the biomolecules would erroneously no longer be detectable in the eluate. It is of interest to prevent this.
The present invention uses, for example, among kits of the substances for the purifying of nucleic acids which are available for example from Invitek (disclosed, for example, in: WO 01/70386, WO 2004/042058, DE 10253351, WO 00/34463, WO 99/32616, U.S. Pat. No. 6,037,465, DE 59610721, DE 4422044 and others). Specifically, the present invention uses magnetizable particles adapted to temporarily bind the biomolecules, thus rendering the biomolecules transportable.
The kits of the substances by Invitek require temperatures of up to 90° Celsius over a period of, for example, 20 minutes. The temperatures of up to 90° Celsius are required during the lysis of the sample material. Sometimes large sample volumes have to be processed. The large sample volumes are not provided by conventional incubation systems. The conventional incubation systems may further not withstand the temperatures of up to 90° Celsius during the lysis of the sample material. Therefore special types of incubators are required.
Furthermore a required sample volume varies with a desired yield of biomolecules. The required sample volume depends very strongly on the field of application. Consequently, in practice problems have frequently occurred with an apparatus that can only cover a predetermined, narrow volume range in an automated processing.